Tracking device for player pianos



e. P.-BRAND. TRACKING DEVICE FOR PLAYER FYIANOS 51,422,824; Patented Ju1 y18, 1922.

. 5 SHEETS-SHEET l- W W qm G. P. BRAND.

' .TRACKING DEVICE FOR PLAYER PIANOS.

APPLICATION FILED OCT, 25,1917. 1,422,824; Patented July 18, 1922.

5 SHEETS-SHEET 2.

. Jnvwwtqz George I: ,Bn'rna e, P. BRAND. TRACKING DEVICE FOR PLAYER PIANOS.

I APPLICATION FILED OCT 25y I9I7- 1,422,824. Patented July 18, 1922.

5 SHEETS-SHEET 3- SwbwvvIIo L 60013622530217. Gamma! e. P. BRAND.

TRACKING DEVICE FOR PLAYER PIANbS.

APPLICATION FAILED OCT. 25, 1917.

Patented July 18, 1922.

5 SHEETS-SHEET 4.

Gepryejfjranfi; 32" 774 5 51mg 1 G. P. BRAND.

TRACKING DEVICE FOR PLAYER PIANOS.

APPLICA TION FILED OCT. 25, 1917.

1,422,824. at t d uly 18, 1922.

5 SHEETSSHEET 5.

Iii-El ill - 3 nve'wiioz Georyeliflrm? 8% Ms W ducts in the tracker bar.

UNITED STATES PATENT OFFICE.

enonsn 1?. BRAND, onunw YOR,K,N.YY.

Specification of Letters Patent.

TRACKING: DEVICE FOR PLAYER PIANOS.

Application filed October 25,1917. Serial No.v198,468.

To (Wu/710m it may concern:

Be it known that I, Gnonon P. BRAND, a citizen of the United States, residing at the city of New York, borough of Bronx, in

the county of Bronx and State of New York,

have invented certain new and useful Improvements in Tracking Devices for Player Pianos, of which the following is a specilication.

This invention is a trackingdevice for player pianos, and relates, more particularly, to pianos of that character wherein the actions are controlled by a perforated music sheet passing over avtracker bar'containing air ducts equal in number to the number of actions.

The principal object of all inventions of this character is to insure proper lateral alinement or registration between the perforations in the music sheet and the air ducts of the tracker bar, while the main dificulty to be overcome is varying widths in the music sheet brought about through imperfect cutting thereof or unevennesses resulting from warping, stretching, or expansion and contraction of the paper from which the sheets are generally made, under the influence of climaticconditions. These deleterious conditions all: tend to seriously affect the lateral alinement between the tracker ducts and music sheet openings, and

great difficulty has been encountered in 0btaining a tracker device which will so control the relation between the music sheet and tracker bar to maintain proper alinementat all times and adequately guard against any and all of the foregoing deleterious conditions.

The most successful tracking devices thus far produced are those which are pneumatically controlled and operateto bring about relative lateral adjustment between the tracker bar and the music sheet. This pneumatic control has generally been dependent for its operation upon the relative position between one edge of the music sheet and air So long as the music sheet is in proper position, it serves to seal the ducts in question, but when it 'moves laterally out of adjustment, one of the ducts is uncovered and air is allowed to pass to the pneumatic controller, which operatesto return the sheet to correct position The chief disadvantage in devices of this character is due to the fact that the, pneumatic controller does not actually maintain I the mus c sheet in properlateral adjustment,

but comes into operation only after the sheet ISOU l', otadjustment, for the purpose of returning it to correct position. This isbecause of the fact thatthe music sheet must move sutliciently away from its true path to uncover one ot the ducts before the pneumatic controller can be brought into operation. \Vith music sheets of different widths, such as those made by different manufacturers, the pneumatic control, depending upon the uncovering of ducts in the tracker bar, is practically inoperative. This is due to the fact that uniform sheet'widths are required to obtainthe adjustment desired.

Another disadvantage inherent in pneumatically controlled-tracker devices of the character described, as well as others, is that there is always considerable leakage, which makes it practically, impossible to obtain constant or uniform air pressure. In the absence of uniform pressure, the controlling means cannot possibly operate in a uniform manner. In all prior tracking devices, the lateral adjustment between the tracker bar and the music sheetis dependent upon air pressure which should be constant or uniform. and, since such uniformity is practically impossible, the: maintenance of the perforations ot the music sheet at all times in absolute registration with the action controlling air ducts in the tracker bar, is not obtained. v

l urthermore, pneumatically operating devices operate relatively slow, so that a de fective music sheet, having an uneven edge,

'willnot produce a quick enough response by the pneumatic controlling means to compensate for the varying contour of the edge, and said sheet will get out of adjustment, and stay out of adjustment until a smoother portion of the edge of the sheet is reached. This last mentioned difiiculty is encountered inall pneumatically controlled tracking devices which depend for their operation upon means adaptedtorest against the edge of the music sheet during the playing operation.

l/Vith the foregoing. considerations in mind, the objects of the present invention are to provide a purely mechanical tracker, thereby obviating failure of the device to properly operate due to leakage, as heretofore; to provide a purely mechanical tracker which will actually maintain the music sheet Patented July 18], 1922.

in proper position for correct tracking, and will not require the movement of said sheet out of position before the tracking device becomes operative, as is the case with pneumatic trackers; to provide a mechanical tracker which is extremely sensitive and which will operate with great rapidity, without tearing the music sheet or causing tliraying oil? the edges thereof; and to obtain maximum simplicity in such a structure and one which cannot tail to operate in correcting all imperfections in the music sheet, due either to imperfect manufacture or climatic changes. A further object of the invention is the provision of a tracking device which is automatically adjustable to music sheets of slightly varying widths and will thus bring about proper tracking of any particular instrument when cooperating with music sheets oi different makes.

A. further salient feature of the invention is to provide a i'i'iechai'iical tracker whirh will. operate perfectly on any music sheet and without requiring any adjustments whatsoever after the tracker has been initially installed and properly adjusted.

In tracker devices as heretofore constructed, it has been necessary for the music sheet to be deflected a clearly perceptible distance from its normal path before it could actuate certain mechanisms for the purpose of returning the sheet to said normal path, and this necessarily meantthat the music sheet would be out oli alinement for a substantial period of time. The present invention, in contradistinction, does not require that the music sheet be so deflected, but, on the contrary, the very slightest attempt by said sheet to move laterally is suliicient to actuate the tracking means and assure the maintenance of perfect alinement, the result being that there is no misalinement, in the ordinary sense 01 the term. In this respect, the invention embodies an entirely new principle oi operation.

Features of the invention, other than those specified, as well as the advantages thereof, will be apparent from the hereinafter detailed description taken in conjunction with the accompanying drawings.

in the accompanying drawings I have illustrated different practical embodiments he invention, but the constructions therein shown are to be understood as illustrative, only, and not as defining the limits of the invent-ion l igure l is a front elevation of the :lrame of an automatic player piano, on which are mounted the tracker bar, the music feed and take-up rolls, and the conjunctive devices for operating said rolls, in combination with wnich is shown a tracking device embodying the present invention.

' 'q'ure is a horizontal section taken in 1 the plane of the line 2-2 of Figure 1, show Figure 5 is a section in the plane of the line 5-5 of Figure 2.

Figure 6 is a section on line 6-6 ol 1? 1gure Figure 7 is a plan view oil the power parts of the tracking device shown in Figures 1 and 52.

Figure 8 is a view similar to lligurc 2, but tinting a modified and simplified form of tracking means.

V Lie 5) a front elevation oi the lel't ham end of the structure shown in lligure 8.

Figure 1.0 is a detail end elevation, on a, large scale, of the modified. form of tracking device shown in Figures 8 and 9, said view being taken as viewed in right angular relation to the plane of the line 10-1O of Fig are 8.

Figure 11 is a section on the line ll.-1'l of Figure 10.

Figure 12 is a detail elevation of certain clutch mechanism which is preterably employcd, and

Figure 13 is a section on line 13-13 of Figure 12.

In order that the present invention may be clearly.- inidcrstood, the parts of a player ptno with which the tracking device is associated and cooperates are shown in the drawings. These parts embody the usual tra neharingzi inrrallel sides A. A and a back AF all oi which are rigidly mounted within the case of a piano. Substantially midway of the height 0' the sides A and A, and near the tlim'u'ard cugc thcrcoi, are secured the opposite ends oi" the tracker bar ll, and beneath tracker bar ll is rotatably mounted the takeup roll 0, while above the tracker bar, and attending through the sides A and A, are the two trunnions, D and l which carry the music roll. Trunniou D is mounted for longitudinal, sliding movement and has associatcd therewith a spring d 'l or normally a dvancing sa d trunnimi and forcing the opposite cud oi the music roll tightly against trunnion l ilrunnion ll also mounted. for longitudinal, sliding movement, as well as iOi'lU'tiLlTf movement, and is provided with an operating stem 0 which passes through the side A of the frame and is journaled near its outer end in a bracket F secured by screws 7 to id side A. When a music roll is support ed on trunnions D and E, in the usual man nor, and main ned in engagement with said trunnions l i by v 'tue oi the sprii'i 's rZ, rotary movement be imparted thereto, as in reaiiit winding, by means of a sprocket wheel f fixed on stem 6, and with whichis associated a sprocket chain encircling a sprocket g loose on drive shaft G, which is journaled for rotation in bracket- F.

At the outer end of shaft Gr is fixed a prime moving sprocket g driven from wellknown mechanism, and slidably mounted on the shaft is the usual clutch 9 provided with a pin adapted to cooperate with a pin g on sprocket g, when the clutch is moved in one direction, and having formed thereon a gear ;7? adapted to cooperate with a gear 0, fixed on the shaft 0 of the take-up roll (1, when moved in the other direction. a

Clutch g is slid longitudinally of shaft G by means of an arm it fixed on rockshaft H journalcd in bracket F, and movement to which is imparted by a second arm It connected with the usual mechanism of tion are well known in the player art and have been described in order that the following detailed description of the mechanism of this invention, as well as the opera tion thereof, may be clearly understood.

As heretofore stated, trunnion E and stem 6 are mounted for longitudinal movement, while the spring 65 of the other trunnion, operating through the music: roll, normally tends to force trunnion E outwardly through the side A. The degree to which such movement of trunnion E is capable limited by a finger 2' mounted on the rock-shaft I, which is journaled in lugs on bracket F, and movement of the rock-shaft is controlled through a link J cooperating, at one end, with an arm fixed to rock-shaft I, and at the other end with either the mechanism shown in detailin Figures 5, Gand 7, or that shown in Figures 10 and if, both of which will be hereinafter more fully described. The mech anism in question serves to move the link longitudinally, thereby oscillating finger 2' in a direction toward or away from trunnion E, and by this operation themusic roll is shifted longitudinally and in parallel relation to the tracker bar. It will be understood that,during this operation, the receding of finger i from the end of stem 0 will allow spring (Z to shift the music roll to the right in Figure 1, while the forward movement of saidfinger will shift the music roll to the left against the tension of spring (Z.

In this manner, the music sheet will be shift ed bodily in alateral direction relative to the air ducts bin the tracker bar.

I will now proceed to describe the further tracker mechanism shown in Figures 1 to T, and will, thereafter, set forth in detail that shown in Figures 8 to 13. The mechanism for positively operating link J, in the construction of Figures 1 to 7, is shown in detail in Figures 5, 6 and 7. It embodies a supporting casing K which is supported in spaced relation laterally of the side A on brackets 7c, as best shown in Figures 1 and 2. Vithinthe side of the casing adjacent the side A is journaled a shaft L which is operatively driven, through sprocket and chain connections Z, from the shaft 0 on which the take-up roll C is mounted. A pawl and ratchet arrangement Z is included in said sprocket and chain connections, so that shaft will be rotated only when the take-up roll is turned in a direction to wind the music sheet upon the take-up roll, said shaft L remaining idle during the rewinding operation.

On shaft L, and interior of easing K, is a. friction disk M, with which cooperates a friction wheel M. Friction wheel M is mounted on a shaft m j ournaled at one end in the front wall of easing K and, at its other end, in a swinging hanger m pivoted on a pin m On the forward end of shaft m is a pinion m which is connected, through a train of gears m m, m and of, to a gear a fixed on a shaft N journaled in both the front and back walls of easing K and extending rearwardly beyond the latter. About shaft N is coiled a helical spring N, one end of which is secured to a collar on fixed on shaft N, while the other end of said spring is hooked over a pin a projecting forwardly from the back wall of the casing. \Vith this construction, it will appear that, if friction wheel M is held tightly against the frictiondisk M, while the music sheet is being rolled upon the takeup roll, shaft m, on which the friction wheel is mounted, will be rotated and will operate, through the train of gears m to m and gear n, to rotate shaft N in a clockwise direction and place spring N under tension. On that portion of shaft N which projects beyond the back of easing K isfixed an arm j, which is pivotally connected to the adjacent end of link J, so that, when shaft N is rotated to place spring N under tension, arm j will be simultaneously oscillated. to push link J longitudinally and, by so doing, shift arm j on shaft I, as hereinbe-fore explained.

Thus, whenever the music sheet is travelling from the music roll to the take-up roll, spring N is being placed under tension and link J is being simultaneously shifted to the right in Figure 1. link the direction specified is limited, to a This shifting of the maximum degree, by means oil a stop a ill- 0d on shalt fl and adapted to engage with the incl ied face a of the bracket in which the rear ends oi the shafts of gears m and m are joururicd, as clearly shown in Figure (3. As soon as stop 14 en aces with said inclined surface, however, u nor rotation of shaft N in a clockwise direction will be precluded, and, it friction wheel M. still engages w" h friction disk irl slipping w'll occur between said parts. it will thus appear that the operation of winding the music sheet upon the take-up roll will serve, through. link Pl, arm j, and rock shatt l, to retract iii'iger ironi the end of oi. the stem 0 0t trunnion E, thereby allowing spring (Z to move the music sheet laterally to the right in Figure 1, and the tendency will be to maintain the roll in. this position until the tight pressure of friction wheel M against friction disk M is sulliciently lessened to oi? tlrce slipping between the parts,

allow whereupon spring ll will oscillate arm j in a couuter-clockwise direction, drawing link J with it and forcing; the music sheet laterally to the left in Figure 1 against the tension of spring (Z.

There are thus, figuratively speaking, two forces opposing one another, namely, that of the spring (Z to move the music sheet to the right, and that of spring N to move it to the lett. 'l. he toree oi spring (Z is always present, whereas spring N is i'iormally held.

in check by the ti ght engagement oi 'triction wheel M with disk M. The wheel ill, however, does not always press tightly against disk M, the degree Off pressure beii h erned by the mechanism next to be described,

which n'icchanism is directly operated or con trolled by engagement. with the music sheet.

The means which coruaerates with the music sheet and by which relative positions between friction wheel M and cooperating disk M are controlled, is best shown in liigzures l and Two brackets 0 and 0 are mounted on the back of the tracker bar and form supports :t'or two pivoted levers and 0", the forward ends oi? which levers extend through slots in the tracker bar and are formed into CQIltlOlllllg steps or note sheet guide fingers 0 and 0, adapted to engage with the edge out the music sheet X, as shown in Figure 2. Levers 0 and o" are normally maintained in engagement with the opposite edges oil the sheet I; by means of springs and 0, rospectivelysecured to said levers and the brackets 0 and 0.

Mounted on bracket 0 is a swinging arm pivoted, at ,2), to said bracket and carry ing near its free end an equalizer lever P pivoted to the swinging arm at a point substantially equidistant from its ends. One end of the equalizer P is connected, through a link 39 to the rear end of lever 0 while the other end of said equalizer is connected,

through a link 22, to the rear end of the other lever 0 'lhrough the interposition ot equalizer P in the connections between the levers 0 and 0 the movement of the stop 0 to the left will cause an equidistant movement of the stop 0 to the right and will thereby allow of the positioning of music sheets 15,01 slightly varying widths, between said stops without in the least el'lfecting pivotal movement of the swinging arm 7), which will remain stationary owing, to the operation of equalizer I. As a matter of fact, the chief function ot lever 0 is to coinpensate for these varying widths of music sheets, said lever operating through equalizer l to shift stop O laterally in synchrouisin with the lateral movement of the slop 0, so that both stops are at all times maintained in engagement with the opposite edges of the music sheet. It w'll be noted. however, that, ii the music sheet X moves laterally to the right in Figure 2, the movement transmitted to lever 0 "through stop 0 will. not be comnumicated to stop 2 in the same manner as vice versa, the push on links 72" and p opposed by spring 0, resulting in the oscillation oil the swinging arm 7) in a counter-clockwise direction. The tree end of arm 79 is connected through links r and with the lower end of h anger m on which is mounted one end oi. the shaft carrying friction wheel. M, so that oscillation oi the swinging arm 72 exerts a thrust, through links Q and 1, upon :t'riction wheel M, thereby ha ng a tendency to move it tree from C1i,2'2lf cii'!0l1l with friction disk M. i'irtirui wheel hl does not, however, actu ally icai'c cont: "t with friction disk hi, since, soon as the pressure which holds said wheel tightly against said disk is released, the wheel immediately slips under the impulse of spring N, thereby causing the feed roll to be moved laterally to the left in Figure 1, or in a direction away from the stop This function results from the fact that,

when spring N is released, it moves link ll longitudinally to the right, and, opeiatiu through arm 7', shaft 1, and finger '11, moves the music roll, which is carried by trunnions D and. E, slightly to the left in Figure 1, against the tension oi? s rin,9; (Z.

Thus, in practice, friction wheel M is always in coi'itact with "Friction disk M. So long: as wheel M is held tightly against the disk, it receives traction therelriimi, but, when this pressure is lessened sulliciently to allow spring N to exert itself, sli ping occurs between these parts. Accordingly, as there no distinct relative movement of wheel M toward or away from disk M, there is no lost motion, and, since the slightest relaxation of pressure between these parts will. allow of the slipping of the friction wheel, the very slightest excess pressure against stop 0, brought about by a tendency of the music sheet to move laterally and destroy the alinement, will cause the parts of the tracking device to come into immediate operation and preclude such lateral move ment of the music sheet. As the slightest excess pressure against stop 0, will bring about this result, the music sheet can never move laterally to destroy the alinement, but is positively maintained at all times in correct position, wherein the alinement will be perfect. Thetracking device of this invention is extremely sensitive, and it is due to this fact that the music/sheet is never allowed to get out of alinement, but is actually maintained in alinement at all times. In this respect, the present invention is a marked advance. over the devices of the prior art. wherein itwas required that the music sheet actually leave its correct position in order to operate means, the function of which was to return the sheet to correct position.

Having described the foregoing construction, its operation, in effecting correct tracking, will be apparent to those skilled in the art, since it will appear that, while spring (Z behind trunnion D normally serves to shift the music roll to the extreme right, as soon as said roll moves far enough in this direction to cause the edge of the music sheet to exert excess pressure on the stop 0, the spring N will be released and the restraining finger 2' will be acted upon by spring N, to oppose the operation of spring cl, i. e., stop the. movement of the sheet to the right. The parts are so adjusted during manufad ture that this position of the forces will bring the music sheet to rest, with the apertures therein in correct registration or alinement with the air ducts b of the tracker bar.

This is the correct tracking position of the music sheet. Accordingly, the slightest tendency of the sheet to deviate laterally from its correct path, during the playing operation, will. cause the immediate operation of the correcting devices to preclude such lateral deviation of the sheet and will serve to maintain the sheet in correct tracking position. In practice, the devices operate so quickly that the. sheet does not have time to move from correct position. before its tendency to move is compensatedfor or overcome by the tracking device. In this respect, the present invention is, as hereinbefore stated, a marked improvement over prior art devices wherein the sheet was required to become out of adjustment to an appreciable extent before the correcting adjuncts could be brought into operation to reiturn the sheet to proper position.

In practice, absolutely perfect sheets are exceptions, rather than the rule, so .that it is found that, in the normal operation of a device embodying this invention, there is a constantoperation of the parts. That is to say, the restraining finger i is practically constantly moving and the pressure between the friction wheel and the friction disk is consequently changing. This is brought aboutby the slight unevenness in the edge and width of practically all music sheets, coupled with the factthat the tracking device is responsive to the slightest variation and serves to instantly compensate therefor. Thus, as the music sheet travels over the tracker bar and each little variation is met with, the tracking device laterally shifts the sheet, first in one direction and then in the other, to individuallycompensate for each variation, so that the perforations are always alined and in perfect registration with the air duct 6 of the tracker bar. \Vhen the mechanism is one initially adjusted, it cannot fail to preserve correct registration, i. e., the perforationsof the music sheet cannot get out of alinement with the ducts of the tracker bar.

- So smoothly does the device operate, however, that, even though it is practically continuously operating, it is noiseless and its presence is not manifest to the operator of the piano. The parts are preferably made quite light, and this applies to the train of gears within casing K. In order that. these gears will not be Sl31'l1)1)8(l01 placed under undue strain when spring N is released,

shaft N has associated therewith stop c which is adapted to engage with shaft on at the conclusion of the unwinding operation of spring N, which forces friction wheel M tightly against disk M, thereby braking wheel M which has been running at high speed during the unwinding operation of the swing, and, by so doing, obviating the necessity of said gears taking up the momentum of the wheel in stopping the same.

.l-Xlthough stops 0 and O are in engagement with the lateral edges of the music sheet at all times during the playing operation, I find it desirable to have them removed from such contact during the rewinding operation, since, by so doing, unnecessary wear. due to the high speed of the sheet during the rcwinding, is obviated. This is accomplished by pivoting a lever S to the bracket 0, as shown in Figures 2 and 3, at substantially the center of said lever. One end of the lever is connected by a link 8 to the arm it which operates the clutch 9 while to the other end of. said lever is connected a link 8' adapted to engage with the lever 0 as shown in Figures 2 and 3, the link 8 serving as a push link and engaging with the edge of the lever, as shown.

With this construction and arrangement of parts, it will be apparent that, when clutch g is in a position to drive the gear 0, link 8 will be retracted to the right and the parts will be in the position shown in Figure 2, to allow of the unrestricted engagement of stopsO and O" with the edge of wear.

Having fully described the details of corn struction and mode of operation of the 6H]- bodiment of the invention illustrated in Fig ures 1 to 7, inclusive, I will now specifically set forth the embodiment of Figures 8 to 13, inclusive. It may be said, in general, that the same broad underlying principle true of the latter construction as is the case in the former, although, in the latter case, the StlUCtLll'O. is greatly simplified and is the one which it is preferred to embody in the practical application of the invention.

The structure of Figures 8 to 13 embodies the usual frame having the parallel sides A A and the back A At the forward edge thereof is mounted the tracker bar B, with its associated air ducts b. The music roll is supported on trunnions, as heretofore, and the take-up roll C is mounted on the shaft 0, which has the sprocket and chain connection Z with the shaft L carrying the friction disk M. Shaft c is driven, as hereinbefore described, through the gear 0, clutch mechanism g and gear 9, and movement is im-- parted to the music roll through the gear g and chain and sprocket connections. as described with reference to the other construe tion. The shaft 1 is provided with the cooperating finger 2', which cooperates with the trunnion E carrying the music roll. and said shaft I is operated by the arm j to which is attached one end of the link J, the construction thus far described being substantially the same as that shown in. Figures 1 and 2, except that in Figure 8 the arm is of less length than that shown in Figures 1 and 2, and the link J is bent to compensate for the lesser length of arm The opposite end of the link J is pivoted at 7' as shown best in Figures 1.0 and 11, to a gear wheel T, which. with other mechanism hereinafter described and including the friction disk BI, is supported on a frame T suspended rigidly on hangers 25 from the left hand end. Gear T is mounted on stub-shaft t and meshes with a pinion U, fixed on the arbor a which, in turn, carries a gear 14. Gear u meshes with the pinion m fixed on the shaft m, which carried the frirti on wil'eel M. The end of shaft on which carries pinion m is journaled for rotation and slight gyration in a rigid element t of hanger T,

as shown best in Figure it), while the opposite end of said saaft is journaled in a swinging stirrup V suspended for oscillation on pin e, which is rigid with hanger T.

By thus supporting the shaft m, friction wheel M may be moved. into or out of engagement with friction disk M through the oscillation. of stirrup V on pin o. In practice, it is not necessary to actually move the friction wheel free from engagement with the friction disk, but, merely, to vary the pressure betv een said parts. In the embodimentof the invention now under discussion, this variance in pressure is governed by one of the stops 0 O, and. said stops are connected, for such operation, with the lower end of stirrup V through the medium of an equalizer W mounted for oscillation on a pin w which is rigid with the stirrup, as shown best in Figure 10.

The stops 0 O are provided, and between them is adapted to operate the music sheet X, which, operating against said stops. serves to control the tracking device in a more simple manner than hercinbefore dc- SflllfJQCl. The stops 0 O are fixed to the forward ends of levers 0 and 0", respectively, which are pivoted on brackets 0 and 0, and with which. are associater springs 0' and 0, which serve the function of impelling stops 0 and 0 toward one another.

Lever 0 is connected through a link 20 with the upper end of equalizer W, while lever 0 is connected by a link on with the lower end of equalizer W. As the result of I this connection, the positioning of a music sheet X between stops 0 and 0 will cause them to be forced apart a distance equal to the width of the sheet, so that said stops will. contact with the opposite edges of said sheet. During this operation, the engagement of the sheet against stop 0 will place tension upon link on, which will serv to rotate equalizer N and place link Q02 under tension for the purpose of moving stop 0 in an op posite direction from the movement of stop (3 and for an equal distance. The pressure against stop 1*, for the purpose of coin- PGUSittlDg' for the difference in width of music sheets, will have a tendency to pull, l

friction wheel M against friction disk M. However, after the sheet is in position. any tendency of said sheet to creep laterally in the direction of stop 0 would place link 10' under compression and tend to rotate the equalizer in a counter-clockwise direction. This rotation of the equalizer will, however, be opposed by the tension of the spring 0 associated with stop 0, and the result will be that, instead of rotating the equalizer to move stop 0 against the tension of spring 0 movement will be imparted to stirrup V and friction wheel M will be moved in a direction away from the friction disk.

If it be assumed that the machine is opertravel of said sheet over the trackerto wind the sheet upon the take-up roll, the spring within trunnion D will be forcing the music roll toward the right and impelling trunnion E, which cooperates with the opposite end thereof, against the finger 2' mounted on shaft I. This will have a tendency to draw the link J toward the right, because of its connection through arm with shaft I, However, when shaft 0 is rotating to operate the take-up roll, the sprocket and chain connection Z is operating to, rotate friction disk M, and, by virtue of friction wheel M, which is in engagement with said disk, operates, through the gearing m a, U and T, to draw said link J to the left in opposition to the power of the spring (Z associated with trunnion D. In the normal operation of the parts, this is what occurs when the sheet is in correct positon. In Figure 11 the relative position of the gearing is shown at a point whereat link J is partially retracted. The retracting of link J is, of course, dependent upon the tight engagement of friction wheel M with disk M, since, as soon as the traction between these parts fails to operate, through the letting up of the pressure, wheel M will slip, and the spring in trunnion D will exert itself and will force the music roll, which carries the music sheet, to the right in Figures 8 and 9.

It will thus appear that, as long as the music sheet is riding smoothly and incorrect position over the tracker, a substantially even pressure will be imposed upon both stops O and O and friction wheel M will be held tightly against disk M. As long as this state prevails, the disk will operate,

, through friction wheel M, to cause a steady retraction of link J and a correspondingly,

steady movement of the music sheet X to the left. However, as soon as the sheet X, by virtue of such movement, begins to exert excess pressure on stop O,-link 102 will be under compression, with the result that the n-essure of wheel M against disk M will be lessened and slipping will occur, bringing about retrograde movement of link J under the impulse of the spring in the trunnion D. There may thus be said to be two forces counteracting each other, namely, the normal operation of the device, which serves, through the friction disk and cooperating connections, to move the entire music sheet to the left, against the tension of the spring trunnion D, while opposed to this operation is the power of spring trunnion D for moving the sheet to the right. Stop 0 may be said to be the stabilizer of the forces, since varying pressures on said stop by the edge of the sheet serves to place one force or the other into operation to maintain the alinenormally exerts on friction disk M.

ment. In view of the fact that this alinement is maintained merely by the changing of the pressure between the friction wheel and the friction disk, actual movement of stop 0 is unnecessary, since the slightest eX- cess pressure exerted thereagainst by the musicsheet will be immediately transmitted I to produce. a corresponding decrease in pressurebetween thefriction disk and wheel,

while a falling of the pressure between stop C) and the music sheet below normal will bring. about a corresponding increase of pressure between the friction disk and wheel. 'Ihe adjustment is of such nicety and the parts are so sensitive to varying pressures that the slightest variation in pressure by the music sheet will be accompanied by a corresponding and instantaneous inverse variation of pressure between the friction disk and wheel, with the result that the music sheet will never become out of position, the slightest tendency in this direction being immediately compensated for. The high degree of sensitiveness is, in a measure, due to the ease with which stop 0 is free to lessen the pressure which friction wheel M In Figure 9, the friction wheel is shown as in engagement with the disk, and, in order to so engage, stirrup V is drawn at its lower end toward said disk and appreciably out of vertical position. Accordingly, as soon as the force which maintains the stirrup out of its vertical position is released, the parts will, of course, immediately tend to gravitate to bring the stirrup vertical. Thus, the action of stop O to decrease the traction between these parts is assisted by gravity, so that, in practice, really no power is required. This is an important feature, since the edge of the music sheet is not actually required to do any work and is, accordingly, not subjected to wear, as would be the case if actual work were required by the edge of said sheet. I

Moreover, through the employment of the equalizer, as in the previously described construction, slight variations in the width of the music sheet are compensated. for and will not serve to throw the sheet out of alinement, as has heretoforeuniversally been the case. i

In the modified construction j ust described, means is also provided for moving stops 0 and O free from engagement with the edges of the sheet during the rewinding operation, and this means is in the form of a single link 8, which is connected with. the clutch operating lever 12,, passes through side wall A of the casing,and is proviced at its inner end with a hook .9 adapted to engage with the inner edge of lever 0 Thus, when lever h is thrown to the right in Figure 8, link .9 will serve todraw stop O to the right, and, through links 20 and 10 and cipuilizer \Vi will bring about the movement o i stop (I to the leil't, where said stops will be entirely free from engagement with the edge of the music sheet during the subsequent rowinding operation. The mere act of returning; the clutch into playing position will automatically release the stops and allow o'l their return, under the impulse of springs 0" and 0 to correct playing position where they will engage with the edges of the music sheet.

it will be apparent trom the foregoing); description of the embodiment of the invention illustrated in Figures 8 to 11, that it is much simpler in construction and more sensitive in its operation than the construction of the preceding figures, although either construc tion ma be employed to great practical advantage over anything heretofore suggested in the art.

In Figures 12 and 13, I have illustrated in detail clutch mechanism between shalt o and the sprocl iet and chain connections Z which drive the "Friction disk. This is a very simple tlorm of clutch and operates with gz reat elliciency. The structure consists in a collar 15 which is lined. upon sh a'lit c by a set-screw 16. Upon collar 15 is rotatably mounted, by a screw 17, a small disk 18 against which the gear 19 is forced by a spring 20. Gear 19 is provided with a plurality oi pockets or apertures 21, with which is adapted to cooperate a linger 22 mounted rigidly on the small disk 18.

As long as shaft 0 is rotated in a counter clockwise direction, with reference to Figure 13, disk 18 will ride on the adjacent surface of gear 19 and, in its attempt to rotate. will force pin 22 tightly against the face oi" said gear, the end of said pin entering one of the pockets 21 and locking the parts togetner ior relative movement. However, it, through inadvertence or otherwise, an at tempt is made to rotate gear 19 in a clockwise direction from shaft 0, the rolling action oi the small disk 18 against the face of said gear will rotate pin 22 out of pocket ill. with which it cooperated, and, gear '10 will remain idle. Thus, during the rewindinp; operation, rear 19 will. remain idle and no movement will be imparted to tho friction disk. In order to preclude the shifting); of pin 22 into a position unnecessarily dista n t from the gear, disk 18 is provided with a notch 23 which cooperates with a stop 2% on sleeve 15 and serves to limit the rotation ol the disk to the predetermined angular travel desired.

The 'loregoing clutch mechanism, while preferably used in carrying out the present nvention, not exclusive, as other clutch mechanisms may be employed if desired. The mechanism shown, however, is highly eliicient and positive in its operation, and is preferred.

It is to be noted that while the Friction wheel ii" and lhc disc iii arc constantly in contact, the traction or pressure ol the onc against the other varies in awordancc with the rarying pines-lire oi, the shcet upon the edge guide, and this varying, pressure is what causes and allows the wheel M to re tale in one direction or the other.

It will be noted that the friction mechanism hereinbotore described. constitutes a clutch.

Havingthus fully described the invention, what I claim as new, and desire to secure by Letters Patent, is:

l. The method of automatically maintaining; registration between the perforations oi? a music sheet and the air ducts oi a tra l'ccr bar, which consists in mechanically ram/in pressure to preserve alinemont without lateral deviation oi the music sheet from its correct position.

9. A Friction wheel arranged. to constant: revolve in one direction. a cooperating lriction wheel constantly in contact 'tlicrlm'itli, and means for varyinf the direction oi rotation of the latter by relaxation or excess of pressure.

3. constantly revolving friction wheel, a friction wheel tor constant conta t therewith, and means operable by variatiruis cl? pressure without ailt'ccting: the alincincnt oi a note sheet for controlling the dirzmtiou o l rotation oi? the last-named friction whorl.

4;. A constantly revolving, friction wheel, a cooperating 'lriction wheel, edge-contactin;;- means. and an oscillatory member opcratircly (UTIUBLlIQCl with said means and morn lc to vary the pressure to cause the lz=,:-.l'--i1itlllQ l wheel to revolve in one direction or the other.

:"i. .x :l ricti on wheel, movable by variations of pressure to change the direction oli rotation oi said wheel, and means constantly in contact therewith 'lor rota ting said wheel in one direction.

(3. friction wheel. moans cilia/lied by ariations oi pressure to change {he div-cction of rotation of said whe l. and means oporativcly conne ted with the first-named means il'or maintaining permanent alineincnt oi the note sheet.

A friction wheel, a cooperating revoluhle member constantly in contact therewith and means controlled by variations oi. pressure to change the direction of rotation oi. said wheel, said means being; at all times in operative relation.

8. A Friction wheel positively 'lrictionallv revoluble in one direction only, and non pneumatic means. affected. by variations in pressure to change the direction of rotation of said wheel.

9. Sheet-centralizing means einl'iodying constantly-in-contact revoluble friction members.

10. Sheet-centralizing means embodying constant]y m-contact revoluble friction members, and :1 sheet zzcthated compensator.

11. Sheet-centralizing means embodying constantlyin-contact friction members and an oscillatory compensator o'peratively connected with one of said members.

12. Sheet-centralizing means embodying constantly in contact friction members, sheet-positioning means embodying an oscillatory member and an oscillatory compensator caried by an oscillatory member of th. ositioiiing means. i

13. Sheet-centralizing means, embodying a constantly-revolving member, a friction wheel constantly in contact therewith and actuated thereby, and means whereby said friction wheel is caused to intermittently reverse its direction of rotation.

i l. Sheet-centralizing means embodying a constantly-revolving member, a friction member actuated thereby and constantly in. contact therewith, and means whereby one of said members is caused to intermittently reverse its direction of rotation.

Sheet-centralizing means embodying a friction meml. er controllable in one movement by a music-spool spring.

1.6. Sheet-centralizing means embodying constantly-in-contact rcvoluble friction members, and ed conne d with and controlling the same.

17. lvheet centralizing means embodying compensating means, sheet-contacting means operatively connected therewith, and a revoluble friction member operatively connected with the compensating means.

1.8. Sheet-centralizing means embodying oscillatory compensating means, and sheetcontacting means operatively connected therewith. i

l9. Edge-contacting means, an oscillatory compensator operating in unison therewith, and friction means operated thereby.

20. Edge-contacting an oscillatory compensator operatin in unison therewitl'i, an oscillatory support for said oscillatory compensator and uponwhich the same is mounted, and friction means operated thereby,

21. A tracker-bar, edge guides having lions protruding beyond said bar. and otally mounted u 011 theot side of porpivsaid fricsaid 1181 bar on stationary rinipports, revoluble tion means, and connections between l e guides and friction means.

is. tracherbar,edge guides having tions extended beyond the said bar, said e guides pivotally mounted on fixed sup 1, friction means and connections between sail friction means and the said edge guides, said (KEKDQCZlORE; being disposed between the pivots of said edge guides and said bar. i A tracker-bar, edge guides pivotally porae-guidin means operatively re volving the mounted on fixed supports and having their free ends extended beyond the bar,.fricti0n means, and means connected with said edge guides between their pivots and free ends and connected with said friction means.

2 Friction means, the membersof which are constantly in contact with each other one member of which moves constantly in one direction during forward. movement of the sheet, and another member movable in either direction and controlled in its movements by pressure of the note sheet while maintaining its centralized position.

25. Friction means movable in one direction only by friction, edge contacting means, and intermediate means for determining the direction of rotation of one of the friction members by variation of pressure exerted by said edge contacting means. i

26.. A friction wheel movable in one direction only by friction, controllable as to its direction of rotation by pressure thereupon.

27. A friction wheel movable in one direction only by friction, and means whereby it is automatically controlled in its direction of rotationby variationsin pressure while the note sheetis maintained in position.

28. A friction wheel movablein one direcsure-exerting means for automatically controlling the direction of rotation of said friction wheel; i a

29. A friction wheel, means for constantly same in one direction, a cooperating friction wheel, a sector actuated thereby, an endwise movable music spool, and connections between the said sector and spool for controlling the movement of the latter in either direction, said cooperating wheel being rotatable in one direction by the first-named wheel, and a spring for rotating it in the opposite direction.

30. Cooperating friction wheels one of which is revolvedin one direction only by friction, a sector operated by one of said wheels, an endwise-removable music spool, and variable pressure means controlled by the music sheet for controlling the direction of rotation of one of said wheels.

31. Cooperating friction wheels one of which is revolved inone direction only by friction, a sector actuated by one of said wheels, an endwise movable music spool. actuated by the sector, and means contacting with the sheet for controlling the movement of one of said friction wheels.

hflechanical means and connections for controlling endwise movement of music spool, cooperatingfriction wheels controlling said spool-moving means, edge-contact ing means for controlling the movements of one of said, wheels, and a spring acting in opposition to'said spool-moving means i In mechanical means for moving a spool endwise in either direction, friction tion only by friction, andoscillatory presmeans for moving it in one direction and non-friction means for moving it in the other direction.

34. Rotatable friction means for causing a music spool to move endwise, said rotatable means rotated in one direction by friction means and rotating in the opposite direction by non-friction means.

35. Rotatable friction means for causing a music spool to move endwise, said rota table means rotated in one direction by friction means and rotating in the opposite direction by non-friction means, and means contacting with the edge of a note sheet for controlling said rotating means.

36. Rotatable friction means one member of which is moved in one direction only by friction, one member of which moves constantly in one direction and the other alternately in opposite directions, combined with variable pressure means for imparting one of the motions to such member.

37. Rotatable friction means, one member of which moves constantly in one direction and the other alternately in opposite directions combined with non-friction variable pressure means for imparting one of the motions to such member.

38. In a web guiding mechanism, rotatable friction means for positioning said web rotating in either direction while in constant contact with a. rotatable friction disc operating in one direction.

89. In a web guiding mechanism, rotatable friction means for positioning said web rotating in either direction while in constant contact with rotatable friction disc operating n one direction, and non-friction means for rotating said rotating means in one direction.

40. In a web guiding mechanisnti, rotatable friction means for positioning said web rotating in either direction while in constant contact with a rotatable friction rise operating in one direction, and edge contacting means for controlling said rotating means.

ll. A 'trackerbar, a music spool and a take-up roll, means for giving endwise movement to the music spool while a note sheet is being wound therefrom upon the talre-up roll, and means whereby the note sheet is maintained against lateral movement in its passage over the trackerbar.

452. traclr rbar, a music spool and a take-up roll, fi ction means for giving end wise movement to the music spool while a note sheet being wound therefrom upon the talc'e up roll, and. means whereby the rude sheet is maintained against lateral movement in its passage over the trackerbar.

l ft .13. traciterbar, a music spool and a takeup roll, means for giving endwise movement to the music spool while a note sheet is being wound therefrom upon the take-up roll, means whereby the note sheet is maintained against lateral movement in its passage over the traclrcrbar, and. means controlled by the note sheet for controlling the music spool moving means.

424:. A trackerbar, a music spool and a take-up roll, means for giving endwise movement to the music spool while a note sheet is being wound therefron'i upon the take-up roll, means whereby the note sheet is maintained against lateral movement in its passage over the trackerbar, and edge contacting means for controlling the spoolmoving means.

if). in a tracking device. the combination of two edge guides, each of which is pivoted rearwardly of the traclrerbar, and each of which projects forwardly to a point forward of the trackerbar, friction means for (01k trolling the lateral positioning of a note sheet, and connections betv-xeen the :lriction means and the edge guiding means indepenth ently and individually.

do. In a tracking device, the combination of two edge guides, each of which is pivoted rearwardiy of the tracl-zerhar and each of which projects forwardly to a point forward of the trackerbar, friction means for controlling the lateral pii sitioning of a note sheet, and connections 1 en the friction means and the edge guiding means indi idually, said connections cooperating with the edge guides intermedia e their tree ends and their points of pivoting.

n. In a tracking device, the combination of two edge guides. each of which pivoted. on f xed supports, rearwardly of the trackerbar and each of which proje ts forwardly to a point forward of the tiaclrerbar, friction means for controlling the lateral posh tioning of a note shed connectimis l e tween the friction means and the edge guid ing means individually. l

-18. In a tracking device, the combination of two guides, each of which pivoted rearwardly of the traclrerbar and each of which projects :lorwardly to a point torward of the ire. roar, friction means for controlling the lateral positioning of a note sheet, and connections between the f iction means and the edge uni-ding means in ilVii lr ally, said connectio eml oilying means for compensating for different widths of note sheets.

49. In a trarl'cing devi e, ;riction clutch mechanism for controlling the lateral positioning of a note sheet, mechanism embodying plurality of cooperating friction clutch elements, ineml'iers contacting with the opposite edges of thi'i sncet and movable thereby for causii ig the slu-iet to be moved in opposite directions when insert ing the music roll, and operative connections between said inembersand the friction clutch elements, said connections including a compensating equalizer for accommodating sheets of different widths.

50. In a device of the character described, a trackerbar, a music sheet associated therewith, mechanism for causing the music sheet to travel over the track erbar, a friction clutch, one member of which is mounted to normally gravitate free from engagement with the other clutch member, in combination with means for normally maintaining the clutch members in tight engagement with one another, and means, controlled by physical contact with the music sheet, for varying the pressures between such clutch members, whereby the music sheet automaticallycontrols its positioning longitudinally of the tracker through its automatic control, the gravitating clutch member serving to render said control highly sensitive to the slightest tendency of the music sheet to move laterally.

51. A clutch memberembodying driving and driven parts, and means mounted on the driving part and operated by the driven part for positively locking the parts together when the driving part is rotated in one direction and automatically releasing the driven part when the driving part is driven in the opposite direction.

52. A friction member constantly movable in one direction, a cooperating friction member moved thereby in one direction, and independent means for moving the said member in the opposite direction.

53, The method of automatically maintaining registration between the perforz tions of a music sheet and the air ducts of a tracker-bamwhich consists in maintaining constant contact of relatively-movable friction members and by variations of pressure preventing perceptible lateral deviation of the music sheet. I

54;. Cooperating revoluble members one of which is revoluble in one direction by contact with the other member and in the other direction by decrease of frictional contact of said members.

55. A friction member, and a cooperating friction member operable in one direction by direct pressure and contactwith the first named member and operable in the opposite direction by slippage or decreased frictional contact of the two members.

56, A. revoluble friction member. and a cooperating revoluble friction member, the

two being in substantially constant contact,

the one being revoluble in one direction by frictional contact of the two and in the opposite direction by non-friction means.

57. A revoluble friction member, and a cooperating revoluble friction member, the two being in substantially constant contact,

the one being revoluble in one direction by frictional contact of the two and in the 0pposite direction by non-friction means made operable upon decrease of such frictional contact.

58. Constantly-operating means controlled by the movement of the note sheet for pre venting lateral deviation of said sheet.

59. constantly operating mechanical means controlled by th movement of the note sheet for preventing lateral deviation of said sheet.

60. Constantly-operating friction means trolling the movement-"of said rotatable member, means for driving said clutch, guiding fingers adapted to engage the music sheet in passage over the tracker bar, and

means connected with said guiding fingers adapted to operate said clutch.

62. in a tracker mechanism. for player pianos, the combination with a tracker bar and rolls supporting a music sheet, of a lever adapted to control the transverse movement of one of the aforesaid members to maintain registration between the music sheet and a tracker bar, a rotatable member pivotally connected with and ope ating said lever, a spur gear secured to said rotatable member, a train of gears connected with said spur gear,.a clutch member operatively connected with said train of gears, a driving clutch member cooperating with the aforesaid clutch, a lever adapted to bring said clutch members into operating contact, guiding fin gers adapted to engage the music sheet in its passage over the tracker bar, and means connecting saio lingers with said clutch operating lever.

63'. In a tracker mechanism for player pianos, the combination with a tracker bar and rolls supporting a music sheet, of a lever adapted to control the transverse movement of one of the aforesaid members to maintain registration between the music sheet and tracker bar, a rotatable member pivotally connected with and operating said lever, aspur gear secured to said rotatable member, a train ofgears connected with said spur gear, a clutch member operatively connected with said train of gears, and support ed on a movable spindle, a driving clutch member rotatably supported on a fixed journal and adapted to be engaged bv the aforesaid clutch member to effect the rota tion ofsaid train of gears, a lever pivotally supported andhaving one end operatively engaging the movable spindle, a pair of guiding fingers arranged one at each side of the music sheet and spring held in contact with the edge of the sheet, a rod connecting the lever controlling the clutch spindle with one of said fingers and. adapted upon the outward movement of the finger to bring the clutch members into operating contact to rotate the train of gears and to operate the lever controlling the alincment of. the music sheet and tracker bar, and a rod connecting the other of said guiding fingers with the lever controlling the -lutch spindle and adapted to release the clutch, and means for effecting the transverse movement of the member effecting the registration between the music sheet and tracker bar.

64. In a tracker mechanism for player pianos. the combination with the tracker bar and rolls supporting a music sheet, of pressure means for moving one of said members transversely, a lever engaging said movable member and adapted to control the transverse movement thereof, a rotatable member pivotally connected with said lever and adapted to swing it upon its pivot, a gear mechanism for swinging said rotatable member, a clutch, a driving mechanism, a clutch interposed between said driving mechanism and said gear mechanism, a pair of guiding fingers arranged one at each side of the music sheet engaging same as it passes over the tracker bar, means connecting one of said fingers with said clutch mechanism and adapted to release the same, and means connecting the other of said fingers with the clutch mechanism and adapted to move the clutch into operating contact, means for re winding the music roll, and means for mov ing the contact fingers out of en,- ;agement with the music sheet during the rewinding.

65. In a tracker mechanism for player pianos, the combination with a stationary tracker bar and a transversely movable music roll, of pressure means for moving said music roll in one direction, a lever member adapted to move the music roll in the opposite direction, a pivotal arm connected with said lever member and adapted to swing said lever to move the roll, a gear mechanism connected with said pivotal arm, a clutch connected with said. gear mechanism, means for driving said clutch coincident with the operation of unwinding the music roll, guiding fingers arranged upon the tracker bar, means connected with one of said guiding fingers for releasing the clutch, and means connected with the other of said guiding fingers for engaging the clutch.

66. In a tracker mechanism for player pianos, the combination with the tracker o and. rolls supporting the music sheet, of a lever adapted to control the transverse movement of one of the aforesaid members to maintain registration between the music sheet and tracker bar, a pivotal member operatively connected with said lever, a gear mechanism operating said pivotal member, a clutch arranged in said gear mechanism having a movable member, a lever adapted to move said clutch into operating engagement, a pivotal arm supported on the outer end. of said lever, a pair of pivotal. guide lingers supported from the tracker bar and engaging the sides of the music sheet, a rod connecting one of said guide fingers with the upper end of the pivotal member on the clutch lever, and a rod connecting the lower end of the pivotal member on the clutch lever with the other guiding finger.

67. In a tracker mechanism for player pianos, a frame, a winding roller supported at the bottom of the frame, a tracker bar supported intermediate of the height of the 'l'rame, a music roll supported at the top of the frame, a driving shaft journaled intermediately between the supporting shafts for said rollers, a sprocket wheel loosely mounted on said driving shaft and operatively connected with a sprocket wheel on the music roll. shaft, said loose sprocket wheel having a laterally projecting tooth, a sleeve slidably mounted upon and rotating with the driving shaft and having at one end a tooth adapted to engage the tooth on said sprocket Wheel and at the other end a spur pinion, a lever supported in the frame an d operatively connected with said sleeve to slide it upon the drivii shaft, a spur gear mounted upon the win roller shaft and adapted to mesh with the pinion of said sleeve, a train of ,e re, a clutch mechanism arranged in said train of gears, a lever connected with said. train of and operatively engaging the :nuisic roll shaft and adapted to move same longitudinally, and. means operatively enthe music sheet and adapted to con trol the operation of said clutch.

68. in a tracker mechanism for player plzUlOS, the combination with a stationary tracker bar and frame support, of a longitudiuallv movable shaft arranged above said tracker bar, a music roll having one end sup brted upon said longitudinally movable shaft a, longitudinally movable spindle supporting the other end of said music roll, means operatively connected. with said spin die to move same longitudinally in one direction, a lever pivotally mounted in the frame and. engaging the outer end of the roll shaft, an arm connected with said lever, a swinging arm pivotally connected to the lever arm, a train of gears operatively connected to said swinging arm, a clutch menr ber interposed in said train of gears, means for operating said train of gears coincident with the unwinding of the music roll, a pair of guiding fingers arranged one at each side of the music sheet and adapted to engage the same in passage over the tracker bar, means operatively connecting said fingers to control said clutch to effect the longitudinal displacement of the music roll in either direction to maintain its register With the tracker bar.

69. Constantly-operating means controlled by the movement of the note-sheet for preventing lateral deviation of said sheet and operative by infinitesimal excess pressure.

In testimony whereof I afiix my signature in the presence of two Witnesses.

GEORGE P. BRAND.

Witnesses i E. H. BOND, E. T. BRANDENBURG. 

